There are a wide variety of security-related tools available for Linux. Many distributions come with a number of these tools, while others are not pre-packaged by distributors for various reasons. Building a security arsenal for penetration testing or vulnerability assessment can be a daunting task if you don't know what tools are good or even what is available.
While a few LiveCD distributions exist to tackle this problem, one that is quite good is BackTrack. This LiveCD can be used as a bootable CD, or you can install it to a USB stick to make it even more portable. As well, BackTrack provides over 300 different tools that can be used by security professionals or system administrators. This includes tools to perform penetration testing on systems, wireless cracking tools, network mapping tools, information gathering tools, vulnerability identification tools, forensics tools, and reverse engineering tools.
You can run BackTrack in a few different ways. It can be installed to a hard drive, just like any other Linux distribution, or it can be run from the LiveCD, installed to a USB keychain device, or installed as a VMware image. For the most portable solution, a USB keychain device works best.
To install BackTrack to a USB keychain, ensure you have a keychain with at least 1GB of space available. Insert the USB keychain device into an existing Linux system.
Mount the bt3final_usb.iso which can be found on the Web site's download page; the version you want to download is the USB Version (Extended). Use:
# mount -o loop -t iso9660 bt3final_usb.iso /mnt/cdrom
Next, format the USB device you plan to use. Insert the device and then umount it; it most likely will get auto-mounted. Make note first of what the device name was (i.e. /dev/sdd).
To format the partition as a FAT16 filesystem use:
# mkfs.msdos /dev/sdd1
Now mount the USB keychain:
# mount /dev/sdd1 /mnt/usb
Next, copy the contents of the ISO to the USB device; if you mounted it to /mnt/usb, use:
# cp -av /mnt/cdrom/* /mnt/usb/
When this is done, move to the USB image on the command-line and execute the bootinst.sh script in the boot/ directory:
# cd /mnt/usb/boot
These commands must be run in the boot/ directory on the USB keychain device! If not, they can possibly overwrite the MBR on the host computer so please be sure you are executing these scripts in the boot/ directory of the USB keychain.
Once this is done, reboot the computer and use the BIOS or boot selector to boot from the USB keychain and BackTrack will load on the computer. At boot you can select from textmode or use Fluxbox or KDE.
Once the system is up and running, the interface is quite useful. With the KDE interface, a number of standard tools are provided such as Firefox and Pidgin, amongst many others. The "BackTrack" menu item then allows you to find the tool you're looking for or explore new ones through its categorized hierarchy.
All told, BackTrack is quite nice. For those who use a laptop and the needs are minimal, BackTrack could function as not only a security toolkit but the primary OS on the laptop as well.
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Vincent Danen works on the Red Hat Security Response Team and lives in Canada. He has been writing about and developing on Linux for over 10 years and is a veteran Mac user.